Buggy code:
private final StringBuffer errorSink ; private IMessageHandler handler ; public BuildArgParser ( PrintWriter writer , IMessageHandler handler ) { } public BuildArgParser ( IMessageHandler handler ) { } public AjBuildConfig genBuildConfig ( String [ ] args ) { } public AjBuildConfig populateBuildConfig ( AjBuildConfig buildConfig , String [ ] args , boolean setClasspath , File configFile ) { } public void printVersion ( ) { } public void printUsage ( ) { } public String getOtherMessages ( boolean flush ) { } private void setDebugOptions ( ) { } private Collection collectSourceRootFiles ( File dir ) { } public List getBootclasspath ( BuildArgParser . AjcConfigParser parser ) { } public List getClasspath ( BuildArgParser . AjcConfigParser parser ) { } private void addExtDirs ( String extdirs , List classpathCollector ) { } private void addClasspath ( String classpath , List classpathCollector ) { } private class AjcConfigParser extends ConfigParser { private String bootclasspath = null ; private String classpath = null ; private String extdirs = null ; private List unparsedArgs = new ArrayList ( ) ; private AjBuildConfig buildConfig ; private IMessageHandler handler ; public AjcConfigParser ( AjBuildConfig buildConfig , IMessageHandler handler ) { } public List getUnparsedArgs ( ) { } public void parseOption ( String arg , LinkedList args ) { int nextArgIndex = ( args . indexOf ( arg ) ) + 1 ; if ( LangUtil . isEmpty ( arg ) ) { showWarning ( "empty<seq2seq4repair_space>arg<seq2seq4repair_space>found" ) ; } else if ( arg . equals ( "-inpath" ) ) { if ( ( args . size ( ) ) > nextArgIndex ) { List inPath = buildConfig . getInpath ( ) ; StringTokenizer st = new StringTokenizer ( ( ( ConfigParser . Arg ) ( args . get ( nextArgIndex ) ) ) . getValue ( ) , File . pathSeparator ) ; while ( st . hasMoreTokens ( ) ) { String filename = st . nextToken ( ) ; File file = makeFile ( filename ) ; if ( ( file . exists ( ) ) && ( FileUtil . hasZipSuffix ( filename ) ) ) { inPath . add ( file ) ; } else { if ( file . isDirectory ( ) ) { inPath . add ( file ) ; } else showError ( ( "bad<seq2seq4repair_space>inpath<seq2seq4repair_space>component:<seq2seq4repair_space>" + filename ) ) ; } } buildConfig . setInPath ( inPath ) ; args . remove ( args . get ( nextArgIndex ) ) ; } } else if ( arg . equals ( "-injars" ) ) { if ( ( args . size ( ) ) > nextArgIndex ) { StringTokenizer st = new StringTokenizer ( ( ( ConfigParser . Arg ) ( args . get ( nextArgIndex ) ) ) . getValue ( ) , File . pathSeparator ) ; while ( st . hasMoreTokens ( ) ) { String filename = st . nextToken ( ) ; File jarFile = makeFile ( filename ) ; if ( ( jarFile . exists ( ) ) && ( FileUtil . hasZipSuffix ( filename ) ) ) { buildConfig . getInJars ( ) . add ( jarFile ) ; } else { File dirFile = makeFile ( filename ) ; if ( dirFile . isDirectory ( ) ) { buildConfig . getInJars ( ) . add ( dirFile ) ; } else showError ( ( "bad<seq2seq4repair_space>injar:<seq2seq4repair_space>" + filename ) ) ; } } args . remove ( args . get ( nextArgIndex ) ) ; } } else if ( arg . equals ( "-aspectpath" ) ) { if ( ( args . size ( ) ) > nextArgIndex ) { StringTokenizer st = new StringTokenizer ( ( ( ConfigParser . Arg ) ( args . get ( nextArgIndex ) ) ) . getValue ( ) , File . pathSeparator ) ; while ( st . hasMoreTokens ( ) ) { String filename = st . nextToken ( ) ; File jarFile = makeFile ( filename ) ; <START_BUG> if ( ( jarFile . exists ( ) ) && ( FileUtil . hasZipSuffix ( filename ) ) ) { <END_BUG> buildConfig . getAspectpath ( ) . add ( jarFile ) ; } else { showError ( ( "bad<seq2seq4repair_space>aspectpath:<seq2seq4repair_space>" + filename ) ) ; } } args . remove ( args . get ( nextArgIndex ) ) ; } } else if ( arg . equals ( "-sourceroots" ) ) { if ( ( args . size ( ) ) > nextArgIndex ) { List sourceRoots = new ArrayList ( ) ; StringTokenizer st = new StringTokenizer ( ( ( ConfigParser . Arg ) ( args . get ( nextArgIndex ) ) ) . getValue ( ) , File . pathSeparator ) ; while ( st . hasMoreTokens ( ) ) { File f = makeFile ( st . nextToken ( ) ) ; if ( ( f . isDirectory ( ) ) && ( f . canRead ( ) ) ) { sourceRoots . add ( f ) ; } else { showError ( ( "bad<seq2seq4repair_space>sourceroot:<seq2seq4repair_space>" + f ) ) ; } } if ( 0 < ( sourceRoots . size ( ) ) ) { buildConfig . setSourceRoots ( sourceRoots ) ; } args . remove ( args . get ( nextArgIndex ) ) ; } else { showError ( "-sourceroots<seq2seq4repair_space>requires<seq2seq4repair_space>list<seq2seq4repair_space>of<seq2seq4repair_space>directories" ) ; } } else if ( arg . equals ( "-outjar" ) ) { if ( ( args . size ( ) ) > nextArgIndex ) { File jarFile = makeFile ( ( ( ConfigParser . Arg ) ( args . get ( nextArgIndex ) ) ) . getValue ( ) ) ; if ( FileUtil . hasZipSuffix ( jarFile ) ) { try { if ( ! ( jarFile . exists ( ) ) ) { jarFile . createNewFile ( ) ; } buildConfig . setOutputJar ( jarFile ) ; } catch ( IOException ioe ) { showError ( ( "unable<seq2seq4repair_space>to<seq2seq4repair_space>create<seq2seq4repair_space>outjar<seq2seq4repair_space>file:<seq2seq4repair_space>" + jarFile ) ) ;

Fix:
if ( ( jarFile . exists ( ) ) && ( ( FileUtil . hasZipSuffix ( filename ) ) || ( jarFile . isDirectory ( ) ) ) ) {